While playing for the Eagles, Barnes made time to help his alma mater, LSU, by spying on the practices of the University of Oklahoma football team prior to the 1950 Sugar Bowl. After being caught by members of the OU football staff and Biloxi, Mississippi residents, Barnes fled to hide in the house of a former LSU teammate, Elbert Manuel. Both Barnes and Manuel refused OU coach Bud Wilkinson's offer to present themselves for identification to clear their names. In the end, the spying incident would have little to do with the outcome of the game, as the superior OU team handled LSU very easily 35-0.[5]

Tiring of small roles and seeing opportunities overseas, Barnes was one of the many American actors who moved to Italy in the early 1960s. Kirk Douglas recommended him for a role in his The Vikings television spinoffTales of the Vikings that was filmed for Douglas' production company in Germany. From 1960 to 1969, he was first active in pirate movies, then Karl May film adaptations and Spaghetti Westerns. His popularity in Germany would lead him to receive top billing when his films played there.[7]

Barnes returned to the United States in 1969 and appeared in more films and television series, which included The High Chaparral. His friendship with Clint Eastwood on Rawhide later lead him to several roles in Eastwood's films. He retired from acting in 1987 and became increasingly ill due to his Diabetes. Barnes died on January 6, 1998. He was the father of German former actress Lara Wendel, who was born Daniela Barnes.